Because of rapid development of modern personal computers, users may easily find that the operating speed and functionality of a Central Processing Unit (CPU) increase day by day. Since Intel launched the CPU working at 25 MHz, computers have kept developing for years and CPUs with operating frequencies of 300, 500, and 600 MHz were introduced continuously. Nowadays, the operating frequency of the CPU in a computer system has reached above 3 GHz. Nonetheless, the prices of CPUs get higher and higher accordingly. Thereby, in order to improve the processing speed of a CPU without purchasing a new one, over-frequency is often adopted. The principle of over-frequency of a CPU is to increase its operating frequency for improving its processing speed.
Currently, over-frequency of a general computer system is achieved by adjusting the core voltage and external frequency (the frequency of system bus) of the CPU. The adjusting method includes adjusting via the Basic Input/Output System (BIOS) or via the Graphical User Interface (GUI). A user configures the relevant parameters. Afterwards, the computer system has to be restarted for executing the new parameters. In addition, because the new parameters might not be appropriate values, the computer system may encounter abnormal start-up or halt without further operations. Alternatively, the computer system may operate unstably, and then encounter problems after a period of time. In such circumstances, it is required to reconfigure the parameters via the BIOS or the GUI until the computer system can start and operate stably. According to the description above, although over-frequency of a CPU may give the highest operating frequency, the adjusting efficiency is extremely low because a user needs to configure the parameters and restart the computer system repeatedly and tediously.
Moreover, from the perspective of a computer system, the computer system might halt, shut down, or even the electronic components, such as the CPU, might be burned caused by the problems of insufficient system power or bad heat dissipation during over-frequency if the maximum tolerance of the total power consumption and the design of power supply, as well as the limitations of the overall heat dissipation, are not taken into considerations. Besides, the current over-frequency designs use fixed parameters. In other words, after the parameters are configured to determine the operating frequency of a CPU, the CPU will operate at this fixed operating frequency once the computer system is restarted. Thereby, under all circumstances, the CPU will process all events using a higher operating frequency. For portable devices containing batteries, the battery time will be reduced drastically once it operates in the battery mode because the CPU is over-frequency operating and consumes higher battery power.
Accordingly, the present invention provides a computer system capable of adjusting the operating frequency dynamically. Not only solving the drawbacks described above, the performance of the computer system is also improved and power is saved as well.